1. Field of the Invention
The invention relates to a bus bar module that electrically connects a plurality of electric storage elements in series.
2. Description of Related Art
Japanese Patent Application Publication No. 2013-143272 describes a cell module including a cell assembly and a bus bar module. The bus bar module includes bus bars each of which connects two unit cells adjacent to each other, cell monitoring integrated circuits that monitor the states (the voltage values) of the unit cells, and terminals that connect the bus bars to the cell monitoring integrated circuits. In this case, the bus bar module includes the plurality of cell monitoring integrated circuits.
When the plurality of cell monitoring integrated circuits are used as in Japanese Patent Application Publication No. 2013-143272, it is preferable to reduce the total number of the cell monitoring integrated circuits as much as possible, in order to, for example, reduce the cost. The number (the maximum number) of the unit cells whose voltage values can be monitored by one cell monitoring integrated circuit has been set. Accordingly, the total number of the cell monitoring integrated circuits can be reduced by assigning the maximum number of the unit cells to one cell monitoring integrated circuit.
When the total number of the unit cells constituting the cell assembly is divided by the maximum number, the total number of the unit cells may not be divisible (a remainder may be left), depending on the total number. In this case, there are one or more remaining unit cells, the number of which corresponds to the remainder and is smaller than the maximum number. When the cell monitoring integrated circuit is operated by electric power supplied from the plurality of unit cells assigned to the cell monitoring integrated circuit, it may not be possible to ensure the voltage value for operating the cell monitoring integrated circuit using the total voltage value of the remaining unit cells.